基于分布参数模型的高压直流输电线路距离保护  

Distance Protection for HVDC Transmission Line Based on Distributed Parameter Model

作　　者：索南加乐[1] 侯卓[1] 宋国兵[1] 张健康[1] 

机构地区：[1]西安交通大学电气工学院,陕西省西安市710049

出　　处：《电力系统自动化》2011年第8期53-57,共5页Automation of Electric Power Systems

基　　金：国家自然科学基金重点项目(51037005);国家自然科学基金资助项目(50877061)~~

摘　　要：对于距离保护而言,没有必要全线准确测距,只要边界准确,能正确区分区内、区外故障即可。文中针对直流输电线路两端连接有平波电抗器,具有明显的边界特征,提出一种高压直流输电线路距离保护时域算法。该方法建立在分布参数模型基础上,通过保护安装处的电压、电流量,计算得到线路末端的电压、电流量,再应用微分方程算法计算出故障距离,以此作为保护动作依据。针对直流线路近端故障时,测距误差大且保护可能拒动的问题,提出了两段式距离保护的解决方法。仿真表明,基于该算法的保护可以正确辨别区内、区外故障,在全线范围内动作快速、可靠。For distance protection,there is no need to determine accurate fault location across the whole line,so long as the border between inside faults and outside faults could be accurately distinguished.Because both terminals of HVDC transmission line are connected to DC smoothing reactor so that it has a clear boundary character,a time-domain distance protection method for HVDC transmission line is proposed.The method is based on the distributed parameter line model.It uses the voltage and current at protection location to calculate them at the terminal of the line.And then the fault distance is calculated with the differential equation.The result is used as action criteria of relay protection.Aimed at problems of large fault location error and possibility of protection refusing to act when the neighbor line fault occurs,the two-segment distance protection is proposed.Simulation results show that the protection based on this algorithm is able to distinguish the fault inside from outside and makes the protection act rapidly and stably within the whole line length.

关 键 词：高压直流 距离保护 分布参数 时域 

分 类 号：TM773[电气工程—电力系统及自动化]